1. Preheat oven to 350 degrees.
2. Rinse the game hens and pat them dry. Seasoni the cavities with salt and pepper and place a quarter lemon and a quarter onion in each cavity.
3. Place the birds, breast side up, in a shallow roasting pan. Dot with butter and sprinkle with salt and pepper.
4. Pour the white wine into the pan. Bakei for 45 minutes to 1 hour, until the juices run clear when the hen is pierced in the thickest part of the thigh.
5. Remove from the oven and serve with the pan juices.